Low-Shock Sampling

MDT tester technique limits pressure drawdown to mitigate shock effects

MDT modular formation dynamics tester

Recover single-phase fluid and protect formation integrity with low-shock fluid extraction

The low-shock technique applied by the MDT modular formation dynamics tester limits pressure drawdown during fluid extraction and sampling. This helps avoid crossing the bubblepoint pressure, which would induce a two-phase condition in the flowline and the sample chambers and compromise representative analysis.

The pumpout module minimizes shock by pumping formation fluids into the MDT tester against piston chambers held at borehole pressure instead of drawing formation fluid into chambers at atmospheric pressure. Pumping continues until an acceptable level of filtrate contamination is reached for downhole fluid analysis (DFA) or diversion of the fluid to a sample chamber.

The dual-packer module can be used with the MDT tester’s low-shock sampling configuration to further reduce the pressure drawdown caused by the area of flow.

Safeguard formation integrity

In addition to enabling single-phase sample recovery, low-shock sampling avoids breaking down the formation while sampling in unconsolidated reservoirs, which would cause the mobilization and flow of sand grains.

Low-Shock Sampling

Low-shock sampling delivers high-quality fluid samples.